'use strict';

function choose_no_repeat_number(collection) {
  collection.sort();
  //在这里写入代码
  var sum = [];
  for (let i = 0; i < collection.length; i++) {
    sum.push(collection[i]);
    for(let j = i+1;j<collection.length;j++){
      if(collection[j]!=collection[i]){
        sum.push(collection[j]);
        i = j;
      }
    }
  }
  return sum;
}

module.exports = choose_no_repeat_number;
